XipCOIN: A Proposal for Decentralized Offline Payments using Ethereum

Offline digital payment systems are currently limited in their scope. Extending them using new technologies like blockchain can expand the offline payment landscape and create new directions for payment systems. This paper proposes XipCOIN as a construction of such a system, based on the Ethereum blockchain. It exploits the recently defined Layer 2 Rollups model of significantly increasing performance and creating desirable transaction characteristics by moving the transactions off the primary Layer 1 blockchain. XipCOIN builds on the approach, established in previous studies by Dmitrienko et al. and Takahashi et al., of using a Trusted Execution Environment to validate the transaction offline by the payee with the payer trusting the payee signature on the confirmation.